George Pólya's four basic principles of problem solving include: 1) Understand the Problem – Clearly identify what is being asked and the relevant information. 2) Devise a Plan – Develop a strategy or approach to solve the problem, which may involve various techniques. 3) Carry Out the Plan – Implement the solution methodically, ensuring to follow the strategy laid out. 4) Review/Reflect – Check the results for accuracy and reflect on the process to learn from the experience.